Photonics Dictionary

A two- or three-dimensional space grating formed when ultrasonic beams with varied paths of propagation intersect.

The optical diffraction spectra formed, or the method that produces them, when a light beam is transmitted through a longitudinal sound field.

An instrument with a fluid that modulates a light beam traversing it because of the effect of ultrasonic waves passing through the fluid.

A light-interference device whose excitation is determined by the modulation of a light beam by an ultrasonic field.

The initiation of the beam in a cathode-ray tube.

Illumination of hologram facets with a beam that covers only a small portion of the hologram in order to optimize laser energy use. See overillumination.

A device used in a free-electron laser to convert the electron-beam's energy into microwave laser radiation by creating a magnetic field of alternating polarity through which the free electrons are...

Array used in coded-aperture imaging experiments with two-beam CO2 lasers that provide an artifact-free process, faithful reproduction of the true image, and more photon collection than the pinhole...

A scanning technique in which the optical density of the film being scanned controls the speed of deflection of the scanning beam.

Short-distance scattering of light in holography caused by random index inhomogeneities and the developing index that interferes with the incident beam, thus recording a hologram of the scattered...

With respect to a television system, a pulse transmitted at the end of each field to break off the cathode-ray beam as it begins the next field.

With respect to television, the returning direction of the electron beam during the vertical blanking period.

Two electrodes that shift the electron beam vertically on a cathode-ray tube screen using electrostatic deflection.

A disc whose surface contains recorded digital data at high-packing densities arranged in concentric rings. The data, representing video frames, are both recorded and read by a laser beam.

An electron tube that stores and visually displays information by means of a cathode-ray-beam-scanning and charge-storage mechanism.

Volume Bragg gratings (VBGs) are specialized optical elements that consist of periodic variations in refractive index throughout the volume of a transparent material, typically a photosensitive glass...

A vortex phase plate is an optical device designed to impart a phase singularity, commonly referred to as a vortex or phase vortex, onto a light beam. This singularity results in a phase profile...

An optical element having two principal axes, slow and fast, that resolve an incident polarized beam into two mutually perpendicular polarized beams. The emerging beam recombines to form a particular...

Any type of interference produced by a beamsplitter.

Gas laser in which the tube acts as a channel for the laser beam.

A beamsplitting mirror that reflects as a function of wavelength.

Also known as cathode-ray tube grid or shield. A cylindrically shaped electrode that, containing the cathode of a cathode-ray tube with opposite potential, is designed to focus and control the...

The Weissenberg method, named after the German physicist Karl Weissenberg, is a technique used in x-ray crystallography for obtaining high-quality diffraction patterns from single crystals. This...

A refractometer that has a greater resolving power than a standard refractometer, and that uses a pentagonal prism to split the light from a single slit into two beams.

A polarizing prism consisting of two calcite prisms cemented such that they deviate the two emerging beams (which are mutually perpendicularly polarized) by nearly equal amounts in opposite...

Two flat parallel electrodes that are vertically mounted alongside each other in a cathode-ray tube and produce horizontal deflection of the beam when a difference of potential is applied between...

The series of processes used to identify and evaluate crystal structure by using crystalline solids to diffract x-rays. In the Laue method, radiation of a wide range of wavelengths is transmitted by...

Irradiation of a cylindrical crystal with an x-ray beam resulting in Bragg diffraction that produces a slightly enlarged image.

Also known as an anticathode. An electrode or electrode section that is focused upon by an electron beam and that emits x-rays.

The method by which Thomas Young in 1802 disproved Newton's corpuscular theory of light by the formation of interference patterns between two beams of light from the same source. This was produced by...

A technique for determining the nonlinear optical properties of a sample material by moving the sample through a focused laser beam and measuring changes in the beam's characteristics, such as...